“To play for the biggest club in the world is a dream come true for me. Louis van Gaal is a fantastic manager and I cannot wait to get started on this new and exciting challenge in my career.”

Romero has previously played under Van Gaal at AZ Alkmaar between 2007 and 2009, and is United’s fifth signing of the summer following the acquisitions of Memphis Depay, Morgan Schneiderlin, Matteo Darmian and Bastian Schweinsteiger.

“Sergio is a very talented goalkeeper,” said Van Gaal. “He was a young keeper during my time at AZ Alkmaar and I am delighted he is joining Manchester United.

Meanwhile, Van Gaal is hoping to keep David De Gea at United but has refused to rule out the possibility of the 24-year-old joining Real Madrid before the end of the transfer window.